Rotation has become an important element in evolutionary models of massive stars, specifically via the prediction of rotational mixing. Here we study a sample of stars, including rapid rotators, to constrain such models and use nitrogen enrichments as a probe of the mixing process. Chemical compositions (C, N, O, Mg, and Si) have been estimated for

We present a catalogue of point-source Hα emission-line objects selected from the INT/WFC Photometric Hα Survey (IPHAS) of the northern Galactic plane. The catalogue covers the magnitude range 13 13) emission-line objects than were previously known in the Milky Way.

The determination of the star formation history of galaxies and the origin of the ISM fuel is one of the main unsolved issues in the study of the formation and evolution of galaxies. By now it appears that supermassive black holes play a major role in regulating the amount of gas, and thus the star formation in their host system. To understand

Ca II triplet spectroscopy has been used to derive stellar metallicities for individual stars in four Large Magellanic Cloud fields situated at galactocentric distances of 3°, 5°, 6°, and 8° to the north of the bar. Observed metallicity distributions show a well-defined peak, with a tail toward low metallicities. The mean metallicity remains

Not Available

Context: Luminous blue compact galaxies, common at z ~ 1 but now relatively rare, show disturbed kinematics in emission lines. Aims: As part of a programme to understand their formation and evolution, we have investigated the stellar dynamics of a number of nearby objects in this class. Methods: We obtained long-slit spectra with VLT/FORS2 in the